The present invention is related to disposable absorbent articles having components that are selectively expandable by the user, such as by inflation.
Disposable absorbent articles are well known in the art. Disposable absorbent articles are used to absorb and retain body exudates, such as urine, fecal material, menses, and the like. A particular desired feature of disposable absorbent articles is the capability to acquire and hold body exudates to eliminate, or at least minimize, leakage of body exudates from between the absorbent article and the wearer.
References in the prior art disclose a cavity or cutout in the absorbent core to receive fecal material. The fecal material passes through the topsheet and is received by the cavity or cutout in the absorbent core. These references suffer from the drawback that a cavity in the absorbent core decreases its absorbent capacity, and that the cavity is limited in volume to the size of the absorbent core. Examples of such teachings include U.S. Pat. No. 2,043,325 issued Jun. 9, 1936 to Jackson, Jr.; U.S. Pat. No. 4,731,065 issued Mar. 15, 1988 to Yamada; U.S. Pat. No. 4,834,737 issued May 30, 1989 to Khan; and U.S. Pat. No. 5,062,840 issued Nov. 5, 1991 to Holt, et al.
Other references teach adding a spacer to the disposable absorbent article. Such spacers can suffer from the drawback that they increase the thickness and bulkiness of the disposable absorbent article, and thereby increase shipping and storage costs. Such spacers may also be perceived by consumers to be uncomfortable because of their thickness and bulk prior to application of the diaper to the wearer. Examples of such references include U.S. Pat. No. 5,171,236, issued Dec. 15, 1992 to Dreier et al.; and U.S. Pat. No. 5,306,266, issued Apr. 26, 1994 to Freeland.
Still other references disclose absorbent articles having inflatable structures. French Patent Application 2,561,078 published Sep. 20, 1985 in the name of Lefebvre discloses a diaper having a structure which is inflatable by mouth. Such inflation can be awkward or inconvenient, especially in public places or when the diaper is already fastened to the wearer. Such an arrangement is also disadvantageous because of sanitary considerations, and because inflation may vary from consumer to consumer, resulting in over or under inflation of the structure and unpredictable product performance.
U.S. Pat. Nos. 3,881,491 and 3,921,232 issued to Whyte on May 6, 1975 and Nov. 25, 1975, respectively, disclose disposable absorbent articles having self inflating structures. The self inflating structures include a wall of semipermeable material and a gas evolving material. Upon exposing the outside of the semipermeable wall of the structure to an activator material, the activator material permeates the structure to interact with the gas evolving material, whereby the structure becomes inflated by evolved gas. The structure taught by Whyte primarily prevents core densification and suffers from the disadvantage that it requires an activator material from an external source (e.g., urine). The wearer may not urinate at the desired time, in the desired location, or in the desired amount to properly inflate the structure. Also, initial inflation of the Whyte structure can separate the gas evolving material from the semipermeable wall, thereby slowing or stopping further inflation of the structure.
Accordingly, it would be advantageous to provide an absorbent article having a component that is expandable. It would also be desirable to provide an absorbent article having a component that is inflatable at the point of use of the absorbent article by a wearer or by a person caring for the wearer, before or after the absorbent article is fastened to the wearer. Further, it would be desirable to provide an absorbent article comprising an inflatable component, a first material, and second activating material separated from the first material by a breakable barrier which can be broken to combine the first and second materials to inflate the component at the point of use of the absorbent article.
In order to solve the problems of the prior art, the present invention is directed to a disposable absorbent article having a topsheet, a backsheet, an absorbent core disposed intermediate the topsheet and backsheet, and an expandable component. The expandable component can expand from a first thickness to a second thickness. The disposable absorbent article further includes a system for controlling the expansion of the expandable component from the first thickness to the second thickness. The system includes a predetermined amount of a first material disposed on the article and a predetermined amount of a second material disposed on the article, wherein the second material is separated from the first material by a breakable barrier. The first and second materials are combinable by breaking the barrier to expand the expandable component. The system further includes an expansion control mechanism which is capable of controlling the rate of expansion of the expandable component.